The long-term objective of the proposed work is the development of innovative detection technologies for biochips (a.k.a. DNA microarrays). It is envisioned that the proposed technologies will enable the application of biochips to biodefense, particularly when a rapid and reliable diagnostic screen is required in the field. The Specific Aims of the proposed work are 1) development of an on-chip signal amplification technique that does not require enzymes, and 2) development of an inexpensive field-portable microarray reader to be used in combination with on-chip amplification. In order to focus initial efforts we have chosen to work in conjunction with NIH funded scientists who are developing a specific application, an influenza A biochip. Because influenza A is an easily transmitted, primarily airborne pathogen, and because this virus can be genetically engineered into novel forms, it represents a serious biodefense concern. In addition, the influenza A virus has a significant impact on human health, with an estimated 500,000 and 1,000,000 deaths worldwide each year, and worldwide surveillance is essential. Finally, influenza A can serve as an excellent model system for development and thorough testing of on-chip signal amplification and a field portable microarray reader. [unreadable] [unreadable] [unreadable]